Draft Revision 6 PWR SGExamination Guidelines

Industry / NRC MeetingAugust 29, 2001

Revision 6 is a draftdocument undergoingutility review according tothe SGMP process. Itmay change beforepublication.

Presentation Outline� Status of Exam Guidelines� Current Issue� SG Exam Guidelines Background� Section 3 � Prescriptive Inspection

Requirements� Section 4 � Performance Based Inspection

Requirements� Section 5 � Degradation Assessments

SG Exam Guidelines Rev 6Status

� Initial resolution of industry comments isclose to completion� Document will be reviewed by the industry

again� Will brief the NRC again when closer to

publication if significant changes aremade

Current Issue

� NRC has expressed concern over theproposed long inspection intervals

� Industry Guidelines allow extendedinspection intervals based on performancehistory, new designs, and improvedmaterials� Checks and balances are included

Chronology of SG ExamGuidelines Revisions� Original Issue, 1981, NDE Center Draft Topical� Revision 1 1984, Formal EPRI Report� Revision 2 1988, Added NSSS Input� Revision 3 1992, Perf. Demo. Requirements� Revision 4 1996, Prescriptive Sampling� Revision 5 1997, Strong Language, �Shalls�� Revision 6 In progress

Current requirement to assess need for revision atleast once every two years

Background

� SG Examination Guidelines is a utilitydeveloped document that has benefitedfrom vendors� input and comments

� Work on draft Revision 6 started in March2000 and is expected to finish in late 2001

� Approval is expected in early 2002

Background� Rev. 6 draft was completed in April and

received industry review during May 1-June 25� 724 comments have been received from utilities

and vendors� All comments will be reviewed, resolved, and

results will be made available to all� Document approval per SGMP Admin Procedures

� This presentation highlights proposed SGinspection interval changes in Rev. 6

Revision 6 Organization� Section 1 - Introduction and Background� Section 2 - Compliance Responsibility� Section 3 - Sampling Requirements for

Prescriptive Based Examinations� Section 4 - Sampling Requirements for

Performance Based examinations� Section 5 - Steam Generator Assessments� Section 6 - System Performance� Section 7 - Summary Requirements� Appendices

Prescriptive Based ExamRequirements - Section 3

Separate sampling requirements for 600 MA,600 TT, and 690 TT materials

600 MA:� Inspect 100% of tubes in each SG every 60

EFPM� SG�s shall be inspected each refueling outage

Prescriptive Based ExamRequirements - Section 3600 TT:� Given SGs are free from active degradation,� Inspect 100% of tubes in each SG in 120, 90, 60, 60,

60,�, EFPMs and with the following conditions:� All inspection periods require supporting DA and OA� Examine at least 50% of tubes in each SG by the refueling outage

nearest the mid-point of the period and the remaining 50% by therefueling outage nearest the end of the period.

� No SG can operate for more than two refueling cycles withoutbeing inspected.

Prescriptive Based ExamRequirements - Section 3600 TT (continued):� If an active damage mechanism is present, the

tubing shall be subject to the same rules asSection 3.3.5 for Alloy 600 MA tubing. Ifsubsequent examinations verify active damagemechanisms are not present, the Alloy 600 MArules still apply.

Prescriptive Based ExamRequirements - Section 3

690 TT:� Given SGs are free from active degradation,

� Inspect 100% of tubes in each SG in 144, 108, 72, 60, 60,60,�, EFPMs with the following conditions:� All inspection periods require supporting DA and OA� Examine at least 50% of tubes in each SG by the refueling outage

nearest the mid-point of the period and the remaining 50% by therefueling outage nearest the end of the period.

� No SG can operate for more than three refueling cycles withoutbeing inspected.

Prescriptive Based ExamRequirements - Section 3690 TT Continued):� If an active damage mechanism is present,

the tubing shall be subject to the samerules as Section 3.3.5 for Alloy 600 MAtubing. If subsequent examinations verifyactive damage mechanisms are notpresent, the alloy 600 MA rules still apply.

600 TT and 690 TT CycleLength Basis� Collective experience

� Plants have accumulated many years of operating experience using 600 TTand 690 TT tubing

� 600 TT plants have operated 15 EFPY with no confirmed corrosion� 690 TT plants have operated 8 EFPY with no confirmed corrosion

� With increasing number of new and replacement steam generators, theaggregate of the 600 TT and 690 TT steam generators are sampled andinspected with increasing frequency

� If any degradation is detected in any 600 TT or 690 TT steam generator, itmust be considered in the degradation assessments of all other plants of thesame tubing material and modify inspection plans accordingly

600TT and 690TT CycleLength Basis� Compensatory measures

� If active degradation is determined at a plant, its cyclelength reverts to 600 MA requirements

� Secondary side requirements address foreign objects

� Program enhancement over existing regulation� Proposed sampling/frequency much more conservative than

the current Tech Spec requirement of 3% every 40 months

Comparison of Rev. 6 Insp.Freq. to Tech. Spec. Reqmt�s12 month cycles CycleCum EFPM

YearRevision 6 (690TT)

100 % Base 100% First ISI 25 % 25% 25% 25%Revision 6 (600 TT)

100 % Base 100% First ISI 25% 25 % 20 % 20 % 20 %Revision 6 (600 MA)

100 % Base 100% 20% 20 % 20 % 20% 20 % 20% 20 % 20% 20 % 20% 20 % 20 %Technical Specification

3 % 3% 3% 3% 3% 3 % 15 month cyclesCycleCUM EFPM

Year

Revision 6 (690) 100 %Baseline 100% first ISI 50% 25% 25 %

Revision 6 (600 TT)100%Baseline 100% first ISI 25% 25% 25% 25 %

Technical Specifications(May be the same 3 %) 3 % 3 % 3 % 3 % 3 % 3 %

2001 2002 2003 2004

1 215

4 5 6345

2008 2009 20102005 2006 2007

30 607

75 90 105

2005 2006 2007 20082001 2002 2003 2004

2014 2015

13511

16010

2012 2013

8

2013

120

2011 2012

9

2011

2014 2015

1 2 3 4 5

2009 2010

8412 13 14

132 144 15612 24 36 48 60 72 9610 11

108 1206 7 8 9

Comparison of Rev. 6 Insp.Freq. to Tech. Spec. Reqmt�s

18 Month Cycles CycleCum EFPM

YearRevision 6 (690TT)

100 % Base 100% First ISIRevision 6 (600 TT)

100 % Base 100% First ISIRevision 6 (600 MA)

100 % Base 100% ISI 33.3% 33.3% 33.3% 33.3% 33.3% 33.3% 33.3% 33.3% 33.3%Technical Specification

3 % 3% 3% 3% 3% 3 % 22 Month CyclesCycleCUM EFPM

Year

Revision 6 (690) 100 %Base 100% first ISI 50% 50%

Revision 6 (600 TT)100%Base 100% first ISI 50% 50% 50%

Technical Specifications(May be the same 3 %) 3 % 3 % 3 % 3 % 3 % 3 % 3 % 3 %

50%

2017

20%

2 3 4 5 6 7 8188 110 13222 44 66 154

2 6 7

20%50% 30%

2012 20132006

2007 2008 2009 20102005 20062001 2002 2003 2004 2014 2015 20162011 2012 2013

162

2016

126

2001 20032002 20052004

50% 50%

2014 20152010 20112007 2008 2009

118 144

8 9 103 4 536 54 72 90 108

Performance Based ExamRequirements � Section 4� Revision 6 changes

� Performance based methodology only applies toadvanced materials

� Concept of performance based inspection was inrevision 5

� Revision 6 adds guidance on methodology� Requirements

� Pre-service inspections and the first in-serviceinspection are the same as in section 3.

Performance Based ExamRequirements � Section 4� Requirements (continued)

� Establishes process to determine subsequentinspection periods

� Basis: EPRI report on deterministic performancebased inspection criteria for steam generators

� No preset inspection frequency� Minimum inspection sample is 20% for

susceptible regions, 100% for regions withdetected mechanisms

Steam Generator Assessments- Section 5

Section 5.2 Degradation Assessments� Degradation assessment is the foundation of SG

inspection program� Requirements

� The design information, operating history, and chemistryhistory for the steam generator shall be documented in theassessment.

� As a minimum, the assessment shall include and documentthinning, pitting, wear, outside diameter IGA/SCC, primary-side SCC and impingement at all susceptible regions withinthe steam generator to determine if an inspection is necessaryand the basis for that conclusion

Steam Generator Assessments- Section 5

� Requirements (continued)� The degradation assessment shall be performed prior to the

PSI of new and replacement steam generators and prior toeach scheduled ISI of steam generators.

� Additionally, a review of the degradation and operationalassessments shall be performed prior to each refueling outagewhen steam generator primary side inspections are notscheduled, to validate the surveillance interval.

Active Damage Mechanism� A combination of ten or more, new

indications of degradation (>= 20% TW) andprevious indications of degradation whichdisplay an average growth rate equal to orgreater than 25% of the repair limit per cyclein any one SG, or

� One or more new or previously identifiedindications of degradation, including cracks,which display a growth greater than or equalto the repair limit in one cycle of operation.